Self return trip cleaner for trenching machines



N. B. SHIMP Aug 21, 1962 SELF RETURN TRIP CLEANER FOR TRENCHING MACHINES 2 Sheets-Sheet 1 Filed Dec. 19, 1958 INVENTOR. N. 13. .5 H M P N. B. SHIMP Aug. 21 1962 SELF RETURN TRIP CLEANER FOR TRENCHING MACHINES 2 Sheets-Sheet 2 Filed Dec. 19, 1958 INVENTOR. M B 5H/MP United States Patent Ofitice 3,49,816 Patented Aug. 21, 1962 3,049,816 SELF RETURN TRIP CLEANER FOR TRENCHING MACES Nathan B. Shirnp, Celina, Ohio, assiguor to Speicher Brothers, Inc., Celina, Ohio, a corporation of Ohio Filed Dec. 19, 1958, Ser. No. 781,513 Claims. (CI. 37-97) This invention rel-ates to trenching machines and particularly to novel means for clearing the digging buckets thereof of material dug by said buckets.

In the art to which this invention relates, many different devices for cleaning buckets have been devised, but such devices have not usually been arranged to permit the passage of lange obstructions or pieces of material which would in some instances cause damage to the machinery or the means for cleaning such buckets.

Usually when trenching machines are required to have means for cleaning or clearing the buckets thereof it is because they are digging in sticky clay-like material for example which clings tenaciousl-y to the interior of the bucket and thus requires means for causing the material to be dropped on to the off bearing conveyor. Such means as heretofore have been provided, however are not able to compensate for obstructions which may be wedged or otherwise positioned in a bucket for example, which obstruction might tend to cause damage if the usual means for clearing the buckets are availed of.

It is therefore a principal object of this invention to provide bucket cleaning means which will operate satisfactorily for all materials and when an obstruction is lodged in a bucket so that ordinary cleaning means would be destroyed, the cleaning means hereof yields and upon passage of the obstruction is again positioned automatically to clear subsequent buckets as they are moved into position to deposit their loads in the off bearing conveyor.

Another object of the invention is to arrange an automatically operating cleaning means in such a manner that while a substantial amount of pressure is necessary to cause the same to yield, at the same time adequate pressure is provided to clear the buckets of all normal materials therein as usually encountered.

Yet another object of the invention is to provide bucket cleaning means which are readily attached or detached from the trenching machine as the case may be and which means are simple in construction and operation and may be adjustable to compensate for various types of material and obstructions which might be encountered during the digging thereof.

Yet another object of this invention is to provide self return trip cleaning means for trenching machines or the like which includes novel latch construction to normally maintain the device in bucket cleaning position and yet be released upon encountering an obstruction which cannot be cleared by the device from the bucket, thereafter when the obstruction has passed, the device is reset automatically for clearing subsequent buckets, the resetting means likewise including novel adjustable instrumentalities.

Other and further objects of the invention will be understood from a consideration of the specification appended hereto and shown in the drawings wherein:

FIGURE 1 is a side elev-ational view of a trenching machine in which the means hereof is embodied, certain elements of the trenching machine itself being langely diagrammatic.

FIGURE 2 is a fragmentary view in elevation, and partly in section showing the relationship on a somewhat enlarged scale of the cleaning device hereof to the structure of the trenching machine proper.

FIGURE 3 is a sectional view and elevational likewise,

disclosing on an enlarged scale the novel latch and positioning means provided in operative positions as the same function in carrying out the objects hereof.

While the invention hereof is disclosed in the drawings as being applied to so called wheel-type trenching machines, it will be readily apparent as this description proceeds that other types of trenching machines may readily avail of the concept hereof and the embodiment disclosed is one which has been found to be particularly suitable for the purposes of carrying out the objects heretofore set forth.

With the foregoing in mind, FIGURE 1 is referred to as disclosing in a largely schematic manner a vehicle generally denoted 1 supported upon wheels such as 2 and 3 being provided with an engine 4 for driving the various instrumentalities including the vehicle itself.

Supported on the vehicle 1 at the rear thereof as on a pedestal 5 is a suitable vertically extending boom 6 connected to the pedestal 5 at its lower end and at its upper end being braced by means of the frame member 8 in which is embodied a hydraulic piston and cylinder unit such as 9 for changing the angle of the digging wheel frame to be described, the connections of the hydraulic piston and cylinder unit 9 being only generally indicated and the source of hydraulic power 10 being under the control of a suitable control panel such as 11.

iMounted so as to be movable upwardly and downwardly along the boom in any preferred manner is a digging wheel frame-work generally denoted 12 pivotally secured at 13 to the boom 6 by means of a shoe such as 14 which will slide upwardly and downwardly on said boom. The frame 12 is supported for vertical pivoting movement by means of suitable cables such as 15 which may be reeved over a pulley 16 and thence to the hydraulic piston and cylinder unit 9 previously mentioned.

As shown the frame '12 is constructed of any suitable material so as to be of rigid form and supported therewithin and depending downwardly therefrom is a digging wheel generally denoted 17 which includes a series of buckets 18 thereon, these being equally spaced around the wheel in accordance with conventional practice.

The wheel 17 is driven by a sprocket such as 19 mounted upon one of the sections of the wheel and operatively engaged with a sprocket 21 suitably mounted on a trans verse shaft 20, the transverse shaft 20 being driven from a gear box 22 carried on one of the frame members 23. The gear box is in turn driven by a chain such as 24 carried over an idler 25 and in turn to a drive gear 26, which is driven by suitable sprocket and chain elements denoted generally 27 from the transmission 28, which is driven from the main transmission 29 by the motor 4 previously mentioned.

Depending from the frame 12 is a further frame 30, suitable pulleys such as 31 and 321 being provided to en gage the inner periphery of the wheel members 17 and guide the same during the digging action, further pulleys 34 on the transverse shaft 20 being furnished to enable three-point bearing of the wheel to be provided.

While the foregoing parts enumerated are generally conventional, the invention is embodied in means for cleaning the buckets as they reach the upper extent of their movement so as to cause material from the buckets 18 to drop on to an off hearing or transverse conveyorsuch as 33, operatively connected to the sprocket drive 21 in any suitable manner and likewise largely conventional.

The trip cleaning mechanism hereof, is shown in somewhat greater detail particularly in FIGURE 3 as embodying a pivoted arm unit 35 which includes the transversely spaced arms 36 and 37 pivoted at 38 to a downwardly extending frame member 30a said arm unit 35 being U- shaped substantially speaking in plan the outer ends being connected by a rectangular tubular member 39.

Extending upwardly from the ends of the arms 36 and 37 are the extension parts 40 and 41 which carry on their upper ends further extensions such as 42, arranged to extend rearwardly and upwardly into the interior of the bucket at its upper extent of travel. These arms 42 will pass through the bucket as it reaches its upper extent and cause material therein to drop downwardly onto the off bearing conveyor 33 previously mentioned.

In order to support the arm unit 35 in the position as indicated in FIGURE 3 in solid lines, a latch structure at the outer end of said larm unit is provided, this latch structure includes a latch plate 43 having a downwardly and rearwardly extending leg 44 integrally fastened thereto, the plate 43 being maintained in position as indicated in FIG- URE 3 on the rectangular tubing 39 by means of a spring unit involving a pin 45, the head 46 of which is adjacent the plate 43 and the pin proper extending downwardly through the tubing 39 and having a spring 47 surrounding the same. At the lower end of the pin a suitable nut 48 and washer 49 are provided to adjust the tension on the spring 47. It will be clear from the foregoing that the latch plate 43 is thus normally maintained in position adjacent the upper surface of the rectangular tubing 39.

The latch plate 43 just described is normally arranged to engage a latch member 50 pivotally connected at 5.1 to the frame member designated 30b, which intersects the frame member 30a and is provided with the pulleys 32 as shown in FIGURE 1. The latch member 50 is intended to engage the extremity of the latch plate 43 and be maintained in that position normally by means of a spring unit 52 carried on a member 53, whereby the member 50 is held in engagement with the downwardly extending leg 44 as well as the outer extremity of the plate 43.

From the foregoing it should be understood that when the pressure downwardly on the arm 35 exceeds a predetermined value, the extremity of the latchplate 43 will be fulcru-med oif of the end of the latch member 50, the portion 44 causing the latch member 50 to move toward the left as viewed in FIGURE 3 around the pivot 51 and thus the edge of the latch plate 43 will escape the upper end of the latch member 50 and move downwardly.

Opposing the forces just mentioned, is a re-setting or return mechanism which includes a yoke 55 of generally U-shaped configuration in plan, having the cross connection 56 and a transverse pin 57 connecting the opposite ends thereof to the transverse piece 56. The pin 57 extends beyond the ends of the yoke and is caused to bear under'the arm members 36 and 37 by means of a spring such as 58 which is fastened to and bears against a plate 59, which plate 59 is secured to the cross pin 57. An adjusting member 60 extends downwardly through the spring 58 and passes through a saddle unit 61, which includes the downwardly extending members 62 and 63 which are secured to braces 64 and 65 respectively, which braces extend between the members 30a and 30b. The saddle 61 is provided with a cross piece 66 through which the part 60 passes, the part 60 being threaded at its outer end and having the suitable lock nuts such as 67 thereon whereby thetensionof the spring 58 may be adjusted.

The transverse piece 56 of the yoke 55 is adjustably related to the arm unit 35 by means of a transverse member'68which is secured to the arms 36 and 3-7. A suitable adjusting bolt 70 with threaded portions thereon is furnished and positioned as shown in FIGURE 3 so that lock nuts;7:1 and 72 may be mounted thereon and regulate the location of the cross piece 56 in relation to the member 68 previously described. This will obviously affect the leverage of the cross pin 57 in its operation against the under side of the arms 36 and 37 within a substantial range and thus accommodate for different types of obstructions which may be encountered by the device.

It should be apparent from the foregoing that when the arm unit 35 pivots around the point 38 it moves downwardly, the spring 58 will be compressed and tend to force the arm unit 35 in a clockwise direction, only being overcome by the obstruction impinging against the extremities of the arm extensions such as 42. Immediately when the obstruction has passed the ends of the arm extensions 42, as carried by a bucket 18, the arm unit 35 will be caused to move in a clockwise direction as described, until it reaches its upward extent of travel as shown in full lines in FIGURE 3, whereupon the latch plate 43 will again be positioned as shown in solid lines in said figure so as to normally maintain the unit 35 in the position shown until another obstruction of such nature as will cause the action previously described in detail to take place is encountered.

It is pointed out that the latch plate 43 may be provided with varying tensions so as to regulate the operation of the latch plate as it may escape the upper end of the latch member 50.

The dotted line disclosure in FIGURE 3 indicates the position of certain of the parts as they will be when an obstruction is encountered and until such time as the obstruction passes the upper ends of the extension arms 42.

The structure herein specifically described in great detail, will of course act in an automatic manner and not require resetting by the operator under any conditions of normal use. The only time when resetting or when adjustment may be desirable is dependent upon the type of dirt which is being encountered by the trenching machine and the possibility of obstructions encountered thereby as having their efi'ect upon the general operation.

I claim:

1. In trencher construction of the class described, in.

combination, a portable frame, trench digging means carried thereby, said means including a series of buckets, carry-off mechanism to receive material from said buckets, and bucket cleaning instrumentalities including obstruction engaging means carried by said frame arranged to engage material in the buckets and cause the same to be directed to the carry-off mechanism, said instrumentalities including releasable means intermediate the obstruction engaging means and the frame whereby the obstruction engaging means is permitted to move out of the path of an immovable obstruction in a bucket, said instrumentalities including different means intermediate the obstruction engaging means and the frame whereby said instrumentalities are automatically returned to operative position after such obstruction has passed the same, said bucket cleaning instrumentalities comprising a pivoted arm connected to the frame, an extension of said arm arranged in position to enter the buckets, latch means to support the arm and extension in bucket cleaning position, said means being releasable when a predetermined pressure is encountered by the extension, and separate means to cause the arm to be returned to latched position after movement therefrom, said latch means including a spring pressed plate carried by the pivoted arm, a pivoted latch member mounted on the frame below the plate and arranged to engage and support the arm by the end of the plate when the arm is in bucket cleaning position, and spring means to maintain said member in plate engaging position, an obstruction causing said plate to slip past the end aforesaid.

2. Trencher construction as claimed in claim 1, wherein the pivoted arm is returned to bucket cleaning position and the member to latched position by resilient means.

3. Trencher construction as claimed in claim 1, wherein return mechanism is provided for the pivoted arm, including a yoke and resilient means engaging the frame and arm and said mechanism is adjustable to vary the rate of return thereof toward cleaning position.

4. In a trench digger having a plurality of buckets movable with respect to a relatively fixed support and a cleaning element coating therewith, means for movably mounting said cleaning element, and means for effecting bias force thereon to normal cleaning position With re spect to said buckets, and resiliently engageable latch means for latching said cleaning element in said position carried intermediate said cleaning element and said fixed support, said latch means being normally engaged to maintain said cleaning element in cleaning position, and yieldable means for maintaining said resilient engagement of said latch means, said yieldable means effecting a predetermined elastic resistance, independent of said bias force, to be overcome by a predetermined stress exerted on said cleaning element by an obstruction in a bucket to permit withdrawal movement of said cleaning element upon disengagement of said latch means and said bias means being operative to effect return of said cleaning element to said normal position upon passing of said obstruction, and means operatively engageable with said latch means to effect reengagement thereof to again maintain said cleaning element in said normal cleaning position.

5. In a trench digger having a plurality of buckets and a cleaning element coacting therewith, means for movably mounting said cleaning element, and means for effecting bias thereof to normal cleaning position with respect to said buckets, and means for latching said cleaning element in said position, comprising a pair of resiliently engageable latch elements, one such latch element being carried by said cleaning element and the other said latch element being normally relatively fixed with respect to said one latch element, said latch elements being normally in engagement to maintain said cleaning element in cleaning position, and yieldable means for maintaining said resilient engagement of said latch elements, said yieldable means effecting a predetermined resistance so as to be overcome by a predetermined stress exerted on said cleaning element by an obstruction in a bucket to permit withdrawal movement of said cleaning element upon disengagement of said latch elements and said bias means being operative to effect return of said cleaning element to said normal position upon passing of said obstruction, and means operative on one of said latch elements to effect reengagement of said latch elements to again maintain said cleaning element in said normal cleaning position.

References Cited in the file of this patent UNITED STATES PATENTS 891,000 Omwake June 16, 1908 983,959 Walters et al. Feb. 14, 1911 1,521,236 Franks Dec. 30, 1924 2,711,035 Pitts June 21, 1955 2,730,821 Fetzner Jan. 17, 1956 2,944,353 Lindell et al. July 12, 1960 

